A non-dyadic lens having a wide field of view having an advantage of acquiring an image including a wider view than a general lens has been in various digital imaging devices including a monitoring system, medical imaging equipment, a vehicular rear camera, and the like. The image acquired through the non-dyadic lens has a disadvantage having significant radial distortion as being distant from the center of the image.
As the image acquired through the non-dyadic lens, a high-resolution image including a lot of information can be acquired at the center, while since non-linear resolution deterioration occurs on the periphery, an overall quality of the image deteriorates.
Various distortion correcting methods have been studied in order to solve such a distortion problem of the dyadic lens. Representatively, Brown describes the radial distortion by using an odd number-th polynomial expression and Tsai proposes an image correcting method in a 3D space by using the odd number-th polynomial expression. Further, Zhang proposes a method for correcting the image by using a plane pattern photographed in various distances and directions and Hughes proposes a method for correcting the image by extracting a vanishing point in the distorted image.
However, since the methods for correcting the distortion in the related art use a linear interpolation method, the methods have a problem in which an aliasing phenomenon increases in a radial direction as being distant from the center of the image.